A number of systems that utilize remote ECG measurements to analyze a cardiac patient's condition have been proposed. These systems include some form of ECG electrodes that are attached to the patient's body and connected to a local processor carried by the patient. The local processor typically includes a transmitter that relays the measurements from the unit worn by the patient to a physician at a remote location. The relay mechanism can utilize a telephone line, either land or cellular, or some form of dedicated transmitter.
This system requires that electrodes be attached to the patient's body. To provide a full 12 lead ECG recording set, electrodes are typically attached to the patient's upper and lower limbs, as well as to a number of locations on the torso. If the patient is in a setting in which the patient has only limited mobility, such a set of attached electrodes may be acceptable; however, if the patient is fully mobile and attending to his or her normal routine outside of a medical environment, temporary or permanent attachment of the electrodes is not usually acceptable and involves a fair amount of discomfort. Furthermore, the electrodes must be removed when the patient bathes. Hence, some arrangement in which the patient or a caregiver places the electrodes on the patient's body at the time an ECG is to be recorded is needed.
A system based on the use of adhesively coated electrodes such as those utilized in normal ECG measurements presents problems from a logistical and cost point of view. The individual electrodes are only usable for a small number of measurements before the adhesive fails. Furthermore, the repeated placement and removal of the electrodes can cause patient discomfort, particularly in patients having body hair in the areas to which the electrodes must be attached.
Systems that utilize electrodes that are held against the body rather than being adhesively attached have been proposed. For example, U.S. Pat. No. 7,112,175 discloses a “glove” having electrodes on the fingertips. If the glove is correctly positioned, a number of ECG measurements can be made; however, the device assumes a constant relationship between the dimensions of the glove and the corresponding ECG measurement points on the patient's body, since the electrode positions are fixed relative to one another. In addition, not all of the measurements provided by the conventional lead ECG tests are provided by the glove.
Finally, the glove must be connected by cables to the transmitter that receives the data and either processes the data or transmits the data to a central processing system. While such arrangements are feasible in the confines of a patient's home, this type of system becomes problematic if the patient is at work or traveling. In this regard, it should be noted that a cardiac patient who is going about his or her normal life may detect an irregularity at any time and wish to verify that he or she is not suffering a cardiac event. The event can occur in any of a number of settings that do not lend themselves to providing a monitoring apparatus and leads for connecting the patient to the apparatus.